What are Construction Practices in Software Engineering Practice? - Part 2 : Testing Principles

In software engineering practice, construction practice includes coding and testing tasks and principles. Testing is a process of finding out an error. A good testing technique is one which gives the maximum probability of finding out an error. The main objective of testers is to design tests that uncover different classes of errors with minimum amount of effort and time.

Some testing principles include:
- From a customer point of view, severe defects are one that cause failure of the program so all the tests that are defined should meet the requirements of the customer.
- Planning of tests should be done long before testing begins. When the design model is made, test cases cab be defined at that very point. Tests can be planned before any code has been generated.
- Generally, individual components are tested first and then the focus is shifted to integrated components and finally the entire system.
- It is not possible to execute different combination of paths during testing. This means that exhaustive testing is not possible.

In a broader software design context, we begin "in the large" by focusing on software architecture and end "in the small" focusing on components. In testing, the focus is reversed.